Such a policing method is already known in the art under the name of Virtual Scheduling Algorithm (VSA) or Continuous Leaky Bucket (CLB) algorithm and is for instance described in the ITU-T Recommendation I.371.
Analysis of the throughput behaviour of a VSA-based policing device for behaving and misbehaving Constant Bit Rate (CBR) connections shows that a small violation of the negotiated cell interarrival time may lead to an excessively high cell discard ratio. Moreover, a fair throughput can not always be guaranteed as, e.g. an above violation of 1% may lead to a cell loss of 50% of all cells, while a violation of 10% may give rise to a cell discard ratio of 30%. Such an analysis is for instance made in the article "Performance analysis of GCRA for CBR sources" by V. K. Samalam et al., ATM Forum contribution 94-0182, March 1994.